This invention is directed primarily to glass block or tile wall construction wherein walls are formed from transparent or translucent hollow glass blocks. In such walls, the blocks are arranged in rows and columns to form a wall, and the blocks are typically joined together using mortar. A difficulty with these blocks and this type of wall construction, however, is that the blocks are quite heavy, and unless elaborate and complicated spacing devices are used, it is only possible to construct a few rows of blocks at a time, because the mortar has to set on the lower rows before it will bear the weight of additional rows formed on top of them. There is also a problem of the alignment of the glass blocks. It usually takes a skilled mason to produce a good looking wall with a smooth surface, evenly spaced blocks and uniform mortar joints.
In order to overcome some of these limitations, it has been proposed to produce blocks formed of transparent or translucent plastic, such as acrylic. The lightweight of the plastic overcomes the weight problem of glass blocks, so that the plastic block walls can be made pretty much to any height desired. However, there is still the problem of the alignment of the blocks, and prior art plastic block walls have been known to be lacking in strength or durability as compared to a well made glass block wall.
Several attempts have been made to address the alignment problem. One example is shown in U.S. Pat. No. 4,648,226 issued to Gerard Manon. This patent shows a glass block having a tongue and groove edge formation. While this would appear to solve the lateral misalignment problem, there is no solution to the longitudinal, or horizontal and vertical misalignment problem, and this Manon block also has a strength problem, since it would appear that the only place for mortar is in the grooves, the depth of the grooves being greater than the width of the ribs or tongues to provide space for the mortar.
U.S. Pat. No. 1,719,620 issued to A. C. Oesterla shows another tongue and groove type construction. This construction also addresses the lateral alignment problem, subject to variations caused by mortar thickness. In addition, horizontal misalignment is taken care of by means of vertical lugs or projections that fit into notches in lower blocks. There is no mechanism, however, to take care of vertical misalignment.
U.S. Pat. No. 3,286,423 shows a block somewhat similar to Manon with the added feature of a connecting device to prevent the horizontal separation of the vertical block walls. While this does not add anything to the alignment of the blocks, it does increase the strength of a wall made from these blocks by preventing horizontal separation of the blocks.